Did mine just over a month ago, and the main thing was - as has been said - to be in the right frame of mind to enjoy it.
You can rehearse some of the RT (if that might be a problem) beforehand - that may help with initial confidence. But I think that confidence builds as you go through it.
Perhaps the most important thing is to keep in mind that, in the nav bit, you are the commander.
Anyway - enjoy it - once you pass you'll be so elated it will be difficult to remember the details until later!